1. Field of the Invention
This invention relates to a process for ozonization of unsaturated organic compounds, more particularly olefins. 2. Discussion of Related Art
Processes for ozonization of unsaturated compounds in which internal cooling is effected by evaporative cooling using coolants boiling above the ozonization temperature, for example water or water-containing emulsions, are known from German Patent publications Nos. 27 13 863, 27 54 366 and 30 05 514. These processes have as one disadvantage that they are not suitable for the low temperature range, for example, ozonization processes which take place below -10.degree. C. (in the case of olefin components capable of entering into secondary reactions at relatively high temperatures). In addition, the evaporative cooling process presupposes that the ratio of ozone to carrier gas is not too high in order to guarantee the necessary evaporation or cooling capacity based on the ozone used (low ozone concentrations).
Low-temperature ozonizations of unsaturated compounds may be carried out, on a small scale, in cooled, jacketed columns with a suitable packing. However, reaction columns such as these involve high costs especially due to the additional heat exchange units required. Further disadvantages include the fact that even with an optimal column design in regard to residence time, a large part of the heat of reaction is released in a confined part of the column. "Stretching" of the reaction zones through the use of several inlets for olefin and ozone does not completely eliminate localized overheating. In prior processes, the scaling up of the reaction column presents considerable design problems on account of the increasing imbalance between the amount of heat to be dissipated and the available heat-exchange capacity; and unavoidable localized overheating resulting in yield losses.
The problems mentioned above are aggravated, in the case of evaporation cooling, by the fact that ozone generators which supply a carrier gas stream containing high concentrations of ozone, for example 100 g ozone per m.sup.3 carrier gas, have recently become available.